It seems like everybody is making honey-garlic ferments these days, but all across the internet, there’s a lurking fear that honey-garlic may secretly harbor botulism. Some of this makes sense – there’s a general misconception that garlic is somehow a high-risk food when it comes to botulism (not true, but widely believed), and of course, new parents are told not to feed babies honey because of a risk of botulism.
So obviously, the safe thing to do is put these together! Well, actually, that’s probably right. Let’s look at the conditions that allow the dormant, spore-form of Clostridium botulinum to germinate and produce botulism toxin:
- An anaerobic (low/no oxygen) environment
- Low acid environment (neutral or alkaline pH)
- Low sugar
- Low salt
- Warm temperatures
- Adequate water/moisture
Let’s go down the list. First, as a process matter, people tend to flip or stir honey-garlic for the first few weeks because the garlic floats. This introduces oxygen into the mixture, which eliminates the anaerobic environment risk.
Second, honey is naturally slightly acidic, although you’d have to test your particular batch to know for certain if it’s below the magic 4.6 pH line, beneath which C. botulinum is inhibited.
Third, honey is a high-sugar environment, which inhibits C. botulinum all by itself.
Fourth, honey is relatively dry. When scientists talk about “water activity” they use the term “aw,” and one paper I saw gave honey an aw of .6. Another mentioned that for C. botulinum to produce toxin, it needs an aw of .95 or higher.
Obviously, the honey-garlic mixture thins, sometimes quite a bit. Is that something to worry about? Maybe – but maybe not. One feature of honey, and why it’s often used as a wound dressing, is that as it hydrates, it produces hydrogen peroxide. It’s not clear whether the concentrations present in a honey-garlic mixture would substantially reduce the spore count, but research does show that H2O2 negatively impacts Clostridium spores.
All in all, it strikes me as exceptionally unlikely that C. botulinum would overcome these five factors and germinate. So mix it up with some garlic in honey, or ginger-honey, or whatever honey mixture strikes your fancy.